{"id":12826,"date":"2022-11-15T18:58:04","date_gmt":"2022-11-15T17:58:04","guid":{"rendered":"https:\/\/www.physiotutors.com\/?post_type=wiki&p=12826"},"modified":"2026-10-15T19:12:14","modified_gmt":"2026-10-15T17:12:14","slug":"low-midline-sill-sign","status":"publish","type":"wiki","link":"https:\/\/www.physiotutors.com\/wiki\/low-midline-sill-sign\/","title":{"rendered":"Low Midline Sill Sign"},"featured_media":12827,"template":"","meta":{"_acf_changed":false,"_relevanssi_hide_post":"","_relevanssi_hide_content":"","_relevanssi_pin_for_all":"","_relevanssi_pin_keywords":"","_relevanssi_unpin_keywords":"","_relevanssi_related_keywords":"","_relevanssi_related_include_ids":"","_relevanssi_related_exclude_ids":"","_relevanssi_related_no_append":"","_relevanssi_related_not_related":"","_relevanssi_related_posts":"","_relevanssi_noindex_reason":""},"class_list":["post-12826","wiki","type-wiki","status-publish","has-post-thumbnail","hentry"],"acf":{"free_access":"","app_link":"","sections":[{"acf_fc_layout":"page-header-detail-page","background":{"background_image":12827,"background_image_alt_text":"Low Midline Sill Sign"},"heading":"Low Midline Sill Sign | Radiographic Lumbar Instability & Spondylolisthesis","subheading":"Lumbar Spine Assessment","content_editor":"","button_type":"internal_link","button_label":"Check our shop","button_style":"button-five","button_internal_link":4646,"button_anchor":"","button_url":"","button_file":null,"label":""},{"acf_fc_layout":"submenu","links":[{"button_type":"anchor","button_label":"Learn","button_internal_link":null,"button_anchor":"section-number-3","button_url":"","button_file":null},{"button_type":"anchor","button_label":"Free course","button_internal_link":null,"button_anchor":"section-number-5","button_url":"","button_file":null},{"button_type":"anchor","button_label":"Assessment E-Book","button_internal_link":null,"button_anchor":"section-number-6","button_url":"","button_file":null}],"dropdown_label":"Go to","button_right":{"button_type":"internal_link","button_label":"Try Premium free","button_style":"button-three","button_internal_link":26802,"button_anchor":"","button_url":"","button_file":""},"button_description":""},{"acf_fc_layout":"content-content","section_options":{"vertical_alignment":"top","column_right_box":false,"column_left_width":"col-12 col-lg-4 offset"},"column_left":{"content_editor":"

Learn<\/h4>"},"column_right":{"content_editor":"

Interspinous Gap Change | Radiographic Lumbar Instability & Spondylolisthesis<\/h2>\nThe Low Midline Sill Sign also known as Slipping Palpation or Step-Off Sign assesses for lumbar spondylolisthesis and radiographic lumbar Instability.\nPetersen et al in 2017 reviewed the literature on assessments used to classify patients with low back pain, which included spondylolisthesis. They report a sensitivity ranging from 60-88% and specificity ranging from 87-100% for the slipping palpation. These ranges and their sometimes-large confidence intervals as well as real-life disturbances such as obesity make it at least moderately useful in the assessment of spondylolisthesis.\n
\n\n[embed]https:\/\/www.youtube.com\/watch?v=sND1YsNZhzo[\/embed]\n\n<\/div>\nConducting this assessment is pretty simple. The patient stands upright with their back exposed. Observe the midline of the back and see if you can spot a sill like a capital \u201cL\u201d. Here is a picture of what it looks like. Then run your thumb down the midline of the spine. In case of a positive test, you would feel that the superior spinous process is displaced anteriorly to the inferior spinous process. Hence the appearance of the sill, which will usually be painful to the touch.\n\nThere are several other orthopedic tests for the diagnosis of radiographic lumbar instability:\n